Thanks for the lists devo22 and Erick Estrada. I'm not too familiar with a lot of those bands as they aren't in my subgenre bubbles but I always appreciate seeing new bands to check out.
My favourites of the year are definitely on the more extreme side of metal subgenres:
Ad Nauseam - Imperative Imperceptible Impulse (technical death metal)
Anatomia - Corporeal Torment (death/doom)
Baest - Necro Sapiens (death)
Cerebral Rot - Excretion of Mortality (death)
Creature - Eloge de l'Ombre (progressive black)
Dipygus - Bushmeat (death)
Dream Unending - Tide Turns Eternal (death/doom)
Fulci - Exhumed Information (death)
Frozen Soul - Crypt of Ice (death)
Full of Hell - Garden of Burning Apparitions (grindcore)
Gargoyle - Hail to the Necrodoom (black/doom)
Hooded Menace - The Tritonus Bell (death/doom)
Mare Cognitum - Solar Paroxysm (atmospheric black)
Morbific - Ominous Seep of Putridity (death)
Replicant - Malignant Reality (death)
Rivers of Nihil - The Work (progressive death)
Swarrrm - I Dreamed... (grindcore)
Thy Catafalque - Vadak (avant garde black / folk metal?)
Vertebra Atlantis - Lustral Purge in Cerulean Bliss (experimental black/death)
Violet Cold - Empire of Love (experimental black)
Worm - Foreverglade (death/doom)
The new albums by Cannibal Corpse, Carcass, Darkthrone, Gojira, Mastodon, etc. were all good too.
The most accessible album I'd recommend is the doom / heavy metal Green Lung - Black Harvest: